4) A singer finds herself with an extra $5,000 at the end of the year. Calculate the annual rates of return for each of the following investments (rounding to the nearest 0.1% where needed). a) She can renovate her home to make it more energy efficient. Doing so will save her, on average, $100 per month on her energy bills. Rate of Return: b) She has a $12,000 of student loan debt, on which she is charged an annual yield of 6.8%. She could reduce this debt to $7,000. Rate of Return: c) She can loan the money to a relative's business, who promises to pay her back $10,000 in 6 years (Assume this loan is safe she's 100% certain that she'll be paid back.). Rate of Return